The research interest of the principal investigator is in the area of physical organic chemistry, with emphasis on the photochemistry of biologically active molecules. Specifically, studies are focused on the developing of new photolabile nicotinamide adenine dinucleotide (NAD+) and psoralen derivatives. The modified coenzyme NAD+ will provide better agents for the photoaffinity labeling process - a technique that is one of the most powerful means for probing enzyme active site, understanding enzyme functionalities, and leading to a control of the biological activity through better pharmaceutical design. The new design will have higher labeling efficiency and are easier to synthesize. Psoralen derivatives are potentially useful in photochemotherapeutic treatment for patients with skin diseases or cancer. The new psoralen derivatives will be much less phototoxic and more effective. The designed molecules will be synthesized and examined for their photosensitivity, reactivity and reaction specificity toward biological environments. The studies will be assisted by use of conventional instrumentation such as GC, GC-MS, FT- IR, NMR, HPLC for product analysis. to evaluate the short-lived reactive intermediates, the principal investigator will employ time-resolved laser spectroscopy and quantum mechanical computation methods. The research projects will equally emphasize training for graduate students and the impact on undergraduate students involved. Graduate students will receive unique and comprehensive training in the interdisciplinary field of physical organic chemistry and photobiology so they can become active and independent researchers in this field. Undergraduate students will be exposed to the research environment and develop interests in pursuing research careers in health-related fields through graduate schools or other health-related institutions.